The potential for and the mechanisms by which reproductive failure and abnormal growth and development are produced by virus infections will be investigated. The principal approach will be observation of the effects of introducing viruses into in vitro models of embryologic processes such as egg cleavage and blastocyst formation, induction and differentiation, and recombination and aggregation of cells dissociated during organogenesis. Clinical studies of the possible involvement of viruses in the etiology of developmental disorders such as biliary atresia, congenital cataracts, and aseptic epiphyseal necrosis will also be undertaken.